Cyclodextrin‐mediated enantioseparation of phenylalanine amide derivatives and amino alcohols by capillary electrophoresis—Role of complexation constants and complex mobilities

Aranyi, Anita; Péter, Antal; Ilisz, István; Fülöp, Ferenc; Scriba, Gerhard K. E.

doi:10.1002/elps.201400142

Cited by 19 publications

(21 citation statements)

References 42 publications

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“…In the case of S‐β‐CD, interestingly, quasi‐equal complex stabilities were accompanied by extremely high enantioresolution values. The observed phenomena can be rationalized based on the large mobility difference of the transient diastereomeric complexes and the mechanism seems to be further proof that CE enantioseparation can be achieved based mostly on this mechanism .…”

Section: Resultsmentioning

confidence: 63%

Validated capillary electrophoretic method for the enantiomeric quality control of R‐praziquantel

et al. 2017

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The enantiomers of praziquantel, the drug of choice in schistosomiasis, were separated by electrokinetic chromatography with cyclodextrins. Nine anionic cyclodextrins were screened for their ability to discriminate between the uncharged enantiomers. Seven investigated selectors presented chiral interactions with the enantiomers, these cases being interpreted in terms of stability constants and complex mobilities. The best results were delivered by sulfated-β-cyclodextrin, where quasi-equal stability constants were accompanied by extreme selectivity values and was explained on the basis of highly different mobilities of the transient diastereomeric complexes. Since the enantiomer migration order was unfavorable, a simple polarity switch was employed (detection end at anode), which apart from migration order reversal, also resulted in extreme resolution values (R > 35) and increased migration times. After optimization (50 mM phosphate buffer pH 2.0, supplied with 15 mM sulfated-β-cyclodextrin, 15 kV, capillary temperature 25°C, short-end injection with 50 mbar × 2 s), analysis time under 10 min were obtained, while still maintaining high resolution (R > 10). The method was validated according to the ICH guidelines and application of the method was tested on in-house synthetized R-praziquantel batches and on commercial, combination tablets containing racemic mixture of the drug.

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Section: Resultsmentioning

confidence: 63%

Validated capillary electrophoretic method for the enantiomeric quality control of R‐praziquantel

et al. 2017

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“…The latter principle was confirmed regarding the migration order of amino acids and peptides under conditions near the p K a ‐value . Other studies reported that the enantioseparation of phenylalanine derivatives using negatively charged CDs is based on mobility differences of the enantiomer‐CD‐complexes . A theoretical background on the concept of enantioseparation by differences in complex mobilities is given by different authors .…”

Section: Introductionmentioning

confidence: 76%

Characterization of complexes between phenethylamine enantiomers and β‐cyclodextrin derivatives by capillary electrophoresis—Determination of binding constants and complex mobilities

et al. 2017

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To optimize chiral separation conditions and to improve the knowledge of enantioseparation, it is important to know the binding constants K between analytes and cyclodextrins and the electrophoretic mobilities of the temporarily formed analyte-cyclodextrin-complexes. K values for complexes between eight phenethylamine enantiomers, namely ephedrine, pseudoephedrine, methylephedrine and norephedrine, and four different β-cyclodextrin derivatives were determined by affinity capillary electrophoresis. The binding constants were calculated from the electrophoretic mobility values of the phenethylamine enantiomers at increasing concentrations of cyclodextrins in running buffer. Three different linear plotting methods (x-reciprocal, y-reciprocal, double reciprocal) and nonlinear regression were used for the determination of binding constants with β-cyclodextrin, (2-hydroxypropyl)-β-cyclodextrin, methyl-β-cyclodextrin and 6-O-α-maltosyl-β-cyclodextrin. The cyclodextrin concentration in a 50 mM phosphate buffer pH 3.0 was varied from 0 to 12 mM. To investigate the influence of the binding constant values on the enantioseparation the observed electrophoretic selectivities were compared with the obtained K values and the calculated enantiomer-cyclodextrin-complex mobilities. The different electrophoretic mobilities of the temporarily formed complexes were crucial factors for the migration order and enantioseparation of ephedrine derivatives. To verify the apparent binding constants determined by capillary electrophoresis, a titration process using ephedrine enantiomers and β-cyclodextrin was carried out. Furthermore, the isothermal titration calorimetry measurements gave information about the thermal properties of the complexes.

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“…Electrokinetic chromatography (EKC) has been widely applied for enantioseparations having the following advantages, high resolution, efficient separation, cost effective and only requires low quantities of samples and [61,84] reagents. Enantiomeric separation occurs in EKC when a chiral selector such as β-CD is added to a pseudostationary phase [85].…”

Section: Mwcnts For Chiral Separation Of Pharmaceuticalsmentioning

confidence: 99%

Application of Carbon Nanotubes in Chiral and Achiral Separations of Pharmaceuticals, Biologics and Chemicals

Hemasa

Naumovski

Maher

et al. 2017

Preprint

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Carbon nanotubes (CNTs) possess unique mechanical, physical, electrical and absorbability properties coupled with their nanometer dimensional scale that renders them extremely valuable for applications in many fields including nanotechnology and chromatographic separation. The aim of this review is to provide an updated overview about the applications of CNTs in chiral and achiral separations of pharmaceuticals, biologics and chemicals. Chiral SWCNTs and MWCNTs have been directly applied for the enantioseparation of pharmaceuticals and biologicals by using them as stationary or pseudostationary phases in chromatographic separation techniques such as high-performance liquid chromatography (HPLC), capillary electrophoresis (CE) and gas chromatography (GC). Achiral MWCNTs have been used for achiral separations as efficient sorbent objects in solid-phase extraction techniques of biochemicals and drugs. Achiral SWCNTs have been applied in achiral separation of biological samples. Achiral SWCNTs and MWCNTs have been also successfully used to separate achiral mixtures of pharmaceuticals and chemicals. Collectively, functionalized CNTs have been indirectly applied in separation science by enhancing the enantioseparation of different chiral selectors whereas, non-functionalized CNTs have shown efficient capabilities for chiral separations by using techniques such as encapsulation or immobilization in polymer monolithic columns.

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Cyclodextrin‐mediated enantioseparation of phenylalanine amide derivatives and amino alcohols by capillary electrophoresis—Role of complexation constants and complex mobilities

Cited by 19 publications

References 42 publications

Validated capillary electrophoretic method for the enantiomeric quality control of R‐praziquantel

Validated capillary electrophoretic method for the enantiomeric quality control of R‐praziquantel

Characterization of complexes between phenethylamine enantiomers and β‐cyclodextrin derivatives by capillary electrophoresis—Determination of binding constants and complex mobilities

Application of Carbon Nanotubes in Chiral and Achiral Separations of Pharmaceuticals, Biologics and Chemicals

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